Device positioning supports

ABSTRACT

A device positioning support for selectively positioning a device in one of a plurality of positions comprising a base, a pair of links which are each connected to the base and to a device, a manually operable self-locking release comprising a biasing member which normally biases a first constraint connected to one of the links into engagement with a second constraint connected to the other link in order to prevent relative movement of the links. The release is manually operable to relieve the biasing force and thereby permit relative movement between the first link relative to the second link in order to reposition the device.

The present invention relates to device positioning supports, such as supports for lamps, which allow a device to be manually positioned in one of a plurality of positions.

BACKGROUND

Various devices have been previously suggested which utilize four-bar linkages or other arrangements comprising two substantially parallel links to support a useful device, such as a lamp, while permitting the selective repositioning of the lamp by the user. Such devices typically rely upon frictional engagement between the links and one or more blocks or slidable “shoes” which are intended to provide sufficient friction to support the lamp in one of a plurality of positions in which it is positioned by the user. Such devices permit the user to overcome the friction by simply forcibly moving the lamp from one position to a new desired position while causing relative movement between the links despite the friction provided by the block or shoe. One disadvantage of such devices is that they often require the use of two hands in order to reposition the lamp and the forces required for the angle adjustment are usually large. Another disadvantage is that the frictional block or shoe often wears or becomes loose over time and requires maintenance, e.g. tightening or replacement.

It would therefore be desirable to provide a device positioning support for selectively positioning a device in one of a plurality of positions which provides a stable and secure support. It would also be desirable to provide embodiments of a device positioning support which can be quickly and easily operated, preferably with one hand.

SUMMARY OF THE INVENTION

One embodiment of the present invention comprises a device positioning support for selectively positioning a device in one of a plurality of positions comprising a base, a first pair of relatively movable links which are each connected to the base and to an intermediate base, a second pair of relatively movable links connected to the intermediate base and to a device, and self-locking releases for fixing the relative positions of the links in each pair of links wherein at least one of the releases is manually operable. In one preferred embodiment the releases are operably connected so that actuation of one release simultaneously actuates the other release. A preferred version of this embodiment comprises a linkage connecting a first one-hand operated release with a second release. Squeezing the first release actuates the second release thereby simultaneously relieving pressure and allowing the disengagement of teeth on two releases with a single squeezing action. This permits two sets of substantially parallel links to be repositioned simultaneously and, preferably, with one hand. In this manner a plurality of pairs of relatively movable links are each provided with a self-locking release and all releases are controlled by the actuation of one or any one of the releases.

One preferred manually operable self-locking release comprises a plurality of relatively movable and engageable teeth and a biasing member which normally biases a first plurality of teeth which are connected to one of the links into engagement with a second plurality of teeth which are connected to the other link in order to prevent relative movement of the links. This release is manually operable to disengage the teeth and/or relieve the biasing force and thereby permit uninhibited relative movement between the respective teeth thereby allowing movement of the first link relative to the second link in order to reposition the device. In one embodiment of the present invention, at least a first plurality of teeth are integrally formed on one of the links.

In one preferred embodiment of the present invention the release comprises a spring-biased clip which comprises the second plurality of teeth. According to this embodiment of the present invention, the spring-biased clip is connected to one of the links, most preferably pivotally connected to one of the links.

Another embodiment of the present invention comprises a base, a pair of generally parallel links which are connected to the base and a device, and a manually operable self-locking release. The linkage preferably comprises a sheathed wire. As used herein, the term “wire” is meant to include a cable or similar flexible strand of material. It is also within the scope of the present invention to have one release out of sight and generally inaccessible to a user, and wherein such hidden release is actuated by the actuation of another release.

According to still further embodiments of the present invention, the links are selectively elongatable in order to further extend the range of possible positions of the lamp or other device. The positioning of the links in one of their possible longitudinal configurations is also preferably controlled by a manually operable self-locking release which is selectively engageable with a third plurality of teeth. The elongatable links preferably comprise a plurality of telescoping elements.

According to a still further embodiment of the present invention, one of the links is at least partially disposed in another link. In one such embodiment, a release for controlling the selective engagement and disengagement of pluralities of teeth is also partially disposed in one of said links. In still other embodiments, the links are not generally parallel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a prior art lamp with the lamp in an uppermost position.

FIG. 2 is a side view of the prior art device of FIG. 1 with the lamp pivoted forwardly.

FIG. 3 is a side view of one embodiment of the present invention.

FIG. 4 is a rear view of the embodiment of FIG. 3.

FIG. 5 is a front view of the embodiment of FIG. 3.

FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 3.

FIG. 6A is a partial, isometric view of the inner side of a clip shown in FIG. 6.

FIG. 7 is a side view of the embodiment of FIG. 1 with the lamp in a forwardly pivoted position.

FIG. 8 is a side view of a second embodiment of the present invention.

FIG. 9 illustrates the embodiment of FIG. 8 with a lamp in a lowered position.

FIG. 10 is a side view of a third embodiment of the present invention

FIG. 11 is a rear view of the embodiment of FIG. 10.

FIG. 12 is a side view of another embodiment of the present invention.

FIG. 13 is a front view of the embodiment of the present invention shown in FIG. 12.

FIG. 14 is a rear view of the embodiment of the present invention shown in FIG. 12.

FIG. 15 is a cross-sectional view taken along lines 15-15 of FIG. 12.

FIG. 16 is a cross-sectional view taken along lines 16-16 of FIG. 12.

FIG. 17 is a side view of the embodiment of the present invention shown in FIG. 12 with the links in an elongated position.

FIG. 18 illustrates the embodiment of the present invention shown in FIG. 12 with the links in an elongated position and the device pivoted forwardly.

FIG. 19 is a side view of a still further embodiment of the present invention.

FIG. 20 is a rear view of the embodiment of the present invention shown in FIG. 19.

FIG. 21 is a cross-sectional view taken along lines 21-21 of FIG. 19.

FIG. 21A is an enlarged view of the circled portion of FIG. 21.

FIG. 22 is a cross-sectional view taken along lines 22-22 of FIG. 21.

FIG. 23 is a cross-sectional view similar to FIG. 21 but with the release actuated to allow repositioning of the light.

FIG. 24 is a cross-sectional view taken along lines 24-24 of FIG. 20.

FIG. 25 is a side view of the embodiment of the present invention shown in FIG. 19 with the light in a forwardly pivoted position.

FIG. 26 is a side view of a still further embodiment of the present invention

FIG. 27 is a rear view of the embodiment of the present invention shown in FIG. 26.

FIG. 28 is a cross-sectional view taken along lines 28-28 of FIG. 26.

FIG. 29 is a cross-sectional view taken along lines 29-29 of FIG. 28.

FIG. 30 is a cross-sectional view similar to FIG. 28 but with the release actuated to allow repositioning of the device.

FIG. 31 is a cross-sectional view taken along lines 31-31 of FIG. 27.

FIG. 32 is a side view of another embodiment of the present invention.

FIG. 33 is a rear view of the embodiment of FIG. 32 with the links at an angle.

FIG. 34 is a side view of the embodiment of the present invention shown in FIG. 32 with the device in a forwardly pivoted position.

DETAILED DESCRIPTION

The various embodiments of the present invention provide significant improvements over supports of the prior art, such as those shown in FIGS. 1 and 2. FIG. 1 illustrates one generally known configuration of the prior art wherein a lamp 1 is connected to a base 2 with a pair of parallel links 3, 4. The links 3, 4 are connected to lamp housing 1 with frictional, pivoting connections 5, 6, respectively. Links 3 and 4 are similarly pivotally connected to base 2 with frictional, pivoting connections 7, 8 respectively. The ability of a user to position lamp housing 1 in different positions relative to base 2 and the ability of the entire support to properly support the light housing 1 in any position to which it is moved depends upon the amount of friction at the frictional, pivoting connections. It will be understood that there must be sufficient friction in these connections to support lamp housing 1, particularly when lamp housing 1 is not disposed directly over base 2. The amount of friction must also not be too great to prevent the movement of the pivotal connection between the links 3, 4, the base 2 and the light housing 1.

The various embodiments of the present invention provide a more secure and stable connection. FIGS. 3-7 illustrate one embodiment of a device positioning support of the present invention which permits selective positioning of a device 10 relative to a base 12. While device 10 will sometimes be described herein as comprising a lamp or lamp housing, the device positioning support of the present invention can be used to permit selective repositioning of other devices including, but not limited to, video monitors, magnifying glasses, trays, book reading supports, frames, work piece holders, displays or other devices. The device itself may have movable elements, e.g. when the device is a rotatable vice a work piece can be clamped to it so that the work piece can be worked on, e.g. painted, from various angles. In some applications, such as involving work pieces, it will be appreciated that frequent repositioning of the device may be required. In all cases, the manually operable self-locking release securely maintains the position of the device under the designed load which includes the weight of the device and support, as well as the weight of anything connected to the device, such as a work piece, plus the forces exerted to the device during normal operation, e.g. forces exerted on a work piece while it is being processed.

According to this embodiment of the present invention, two substantially parallel links 13, 14 connect device 10 with base 12. Base 12 can be connected to a structure, e.g. a desk, that allows rotational and/or translational movement of base 12 relative to such a structure. A forward link 13 is pivotally connected to base 12 by a pivotal connection 17 and to a device 10 with a pivotal connection 15. Rearward link 14 is pivotally connected to base 12 with a pivotal connection 18 and to device 10 with pivotal connection 16. While one or more of the pivotal connections can be a frictional connection, each of the pivotal connections can also be substantially freely rotatable since the stability of the positioning support does not rely upon the friction provided by any of the pivotal connections 15-18. According to this embodiment of the present invention, the positional stability of device 10 relative to base 12 is provided by a manually operable self-locking release 20. The manually operable self-locking release 20 of this illustrated embodiment of the present invention comprises a spring-biased clip 24 comprising engageable teeth which engage a plurality of teeth 22 on right and left sides of link 14. The clip 24 comprises two pivotally mounted arms 21, 31. As best shown in FIGS. 4-6A, a left engagement arm 21 comprises a handle portion 23 and an engagement portion 25 comprising teeth 27. The engagement teeth on the clip 24 are shaped and configured to engage securely with the teeth 22 on link 14. In this embodiment, the teeth are positioned transverse to the direction of relative movement between the links. Arm 21 is pivotally connected to forward link 13 with pin 29. Illustrated link 13 is formed and installed by bonding two pieces together. The vertical position of the clip 24 on link 13 is fixed. In a similar manner, right engagement arm 31 comprises a handle portion 33 and an engagement portion 35 having teeth 37 and is also pivotally connected to link 13 via a pivoting pin 39. A biasing member 30 in the form of a spring is positioned generally between handle portions 23, 33 of engagement arms 21, 31 and normally biases the handle portions outwardly thereby causing the engagement portions and their respective teeth to securely engage teeth 22 on rear link 14.

Due to the generally parallel and spaced positioning of links 13 and 14, in order for device 10 to be repositioned relative to base 12, a point on forward link 13 must move relative to a point on rearward link 14. Relative movement also occurs, but to a different extent, in embodiments where the links are not generally parallel. When relative movement between forward link 13 and rearward link 14 is prevented, the device 10 cannot be repositioned relative to base 12. Thus, to overcome the biasing force of biasing member 30 which normally biases two sets of engageable teeth 27 and 37 of the clip 24 into engagement with teeth 22 on rearward link 14, a user simply squeezes the handle portions 23, 33 together thereby disengaging teeth 27 and 37 from teeth 22 on rearward link 14. While continuing to apply squeezing pressure to the handle portions 23, 33, the handle portions are moved forwardly or rearwardly in order to reposition the device 10 to the desired position. The handle portions are then simply released and biasing member 30 accomplishes the self-locking action by reengaging teeth 27, 37 with teeth 22. Advantageously, a user does not need to actively engage the lock, e.g. by tightening a threaded locking mechanism. By simply releasing the squeezing force, the release securely fixes the relative position of the links.

A comparison of the position of the clip 24 on link 14 in FIG. 3 when the device 10 is positioned directly above base 12 with the same elements in FIG. 7 when the device 10 is positioned forwardly of base 12 illustrates that the clip 24 (which is on the same position of forward link 13) engages a different, more upward, position on rear link 14. This comparison illustrates the relative movement between portions of the links during the repositioning of the device 10 relative to the base 12. While FIG. 7 illustrates one alternative position of device 10 relative to base 12, it will be appreciated that device 10 can be selectively positioned and maintained in any one of a plurality of different positions relative to base 12 utilizing the device positioning support of the present invention.

While teeth 22 in this illustrated embodiment are positioned on a central portion of link 14, it is also within the scope of the present invention to provide teeth 22 along the entire length of rearward link 14, or at positions other than illustrated in the Figures. The positioning of the clip 24 can also be varied without departing from the scope of the present invention. For example, the clip 24 can be positioned on the rear link. While the illustrated teeth are perpendicular to the direction of relative movement between the links, the teeth need not be positioned perpendicular but are preferably generally transverse to the direction of relative movement between the links.

FIGS. 8 and 9 illustrate another embodiment of the present invention. Components of this embodiment are similar to those illustrated in FIGS. 3-7, but the embodiment in FIGS. 8 and 9 comprises two sets of substantially parallel links which are pivotally connected to an intermediate base 53. The intermediate base 53 acts as the base for the links connected to the device. As shown in FIGS. 8-9, this embodiment comprises a device 40, a base 42, a lower forward link 43, an upper forward link 45, a lower rearward link 44, an upper rearward link 46, a lower release 50, an upper release 51, and an intermediate base 53. With the exception of the intermediate base 53 and the reorientation and repositioning of a release, the elements of this embodiment of the present invention are identical to the elements described above in connection with FIGS. 3-7. According to this embodiment, intermediate base 53 provides a pivotal connection between the four links 43-46 and essentially forms two four-bar linkages with the lower four-bar linkage comprising base 42, the two lower links 43, 44 and the intermediate base 53 while the upper four-bar linkage comprises the two upper links 45,46, intermediate base 53 and device 40.

According to this embodiment of the present invention, all of the links can be moved in the same direction, e.g. forwardly, or the links can be pivoted in opposite directions. If all four links illustrated in FIG. 8 are rotated forwardly after actuating releases 50, 51, the device positioning support can be positioned similar to the positioning of the support shown in FIG. 7 but with a longer span assuming that the combined length of the links is longer than those in FIG. 7. Alternatively, the links can be rotated in opposite directions to provide a greater number of possible positions of device 40 relative to base 42. For example, as shown in FIG. 9 the lower links are secured in a forwardly pivoted position while the upper links are secured in a rearwardly, but slightly less angled positioned than the lower links resulting in the device 40 positioned lower and slightly forward when compared to the position of device 40 in FIG. 8. This illustrated embodiment permits the device to be positioned selectively almost anywhere within a semi-circle having a diameter approximately equal to the cumulative length of the 2 sets of links. In embodiments comprising only one set of links, the device can only be positioned near the periphery of an imaginary semi-circle. While base 42, or other bases of the present invention, can be fixed, they can also be mounted on a movable, e.g. rotatable or translatable structure. The semi-circular range of motion described above will become hemispherical when the base is attached to a rotatable structure. While this embodiment comprises two sets of links, i.e. the upper links and lower links, it is also within the scope of the present invention to use a greater number of sets of links. While the bases of the illustrated embodiments are shown as simple rigid structures it is also within the scope of the present invention to provide a device positioning support wherein the base comprises connectors for connecting lower links to a separate rigid structure, such as a desk.

FIGS. 10 and 11 illustrate a further embodiment of the present invention similar to the embodiment illustrated in FIGS. 8 and 9, but wherein the releases are connected with a linkage which coordinates the actuation (opening) of one release with the opening of another release and permits one-handed operation of the entire positioning support. As illustrated in FIGS. 10 and 11, a lower release 70 comprises a handle portion 73 on the rearward side of the positioning support and an engagement portion 75 toward the forward side of the support. An upper release 80 is orientated oppositely so that handle portions 83 are positioned forwardly while engagement portions 85 are positioned rearwardly.

A linkage 90, which in this embodiment of the present invention comprises an inner wire 94 movably disposed in a protective sheath 92, coordinates the opening of the releases 70, 80. Wire 94 is secured to right handle portion 73 of lower release 70 and the right engagement portion 85 of upper release 80. As best shown in FIG. 11, the sheath 92 abuts the left handle portion 74 of lower release 70 and the left engagement portion 86 of upper release 80. The wire 94 normally maintains the release closed since biasing member 72 biases the handle portions of lower release 70 outwardly. This biasing force biases the engagement portions 75 of lower release onto the forward lower link 71. This biasing force is transmitted through wire 92 to bias (draw) engagement portions 85, 86 of upper release 80 into engagement with the corresponding upper rear link 76. It will be appreciated that, in the absence of external force, biasing member 72 keeps both releases in the locked position to maintain the device in the desired position. When the handle portions of release 70 are squeezed together, the tension on wire 92 is relaxed thereby relaxing the biasing force on the corresponding engagement portion of upper release 80 on the teeth on the upper rearward link 76. This permits repositioning of the links. Alternatively, the handle portion of the upper release 80 can be squeezed together thereby opening the upper engagement portions and drawing the lower handle portions closer together against the outwardly directed force of biasing member 72 to increase the tension in wire 92 such that both locks are released. Thus, the squeezing hand is simultaneously releasing the two releases while repositioning the device to a desired position before releasing the squeeze to fix the device in the new position. With reference to FIG. 11 which is a rear view of the embodiment shown in FIG. 10, it will be appreciated that movement of the wire 94 relative to sheath 92 at one end will have the opposite effect at the opposite end of the sheath. For example, compression of handle portions 73 will reduce the amount of wire 94 which is exposed from sheath 92 at the bottom of the linkage thereby causing more wire 94 to be exposed or outside of sheath 92 at the top of the linkage, and vice versa. Therefore, if a user squeezes the handle portions 83 of upper release 80, engagement portions 85, 86 will move away from each other thereby drawing more of wire 94 out the upper end of sheath 92 and consequently pulling more of wire 94 into the lower end of sheath 92. This will squeeze handle portions 73 together and disengage locking member 70 from the teeth on the lower forward link.

According to this embodiment of the present invention, a biasing member, such as the illustrated biasing member 72, can be used with either one or both of the releases. Using the handle portion of the upper release as the primary unlocking handle is preferred since it is closest to the weight of the device. When used in this manner, a spring can also be used to bias release 80 though such a spring is not illustrated in FIGS. 10 and 11.

FIGS. 12-18 illustrate a further embodiment of the present invention wherein links are selectively elongatable in order to increase their effective length. In this illustrated embodiment, each of two links comprises multiple elements which are arranged in a telescoping fashion to allow the effective lengths of the links to be changed, either increased or decreased, as desired. This embodiment advantageously utilizes a single self-locking release to secure the relative positions of the links in a manner similar to the operation of the embodiment discussed above in connection with FIGS. 3-7, and to also fix the longitudinal configuration, i.e. the degree of elongation or shortening, of the links.

According to this embodiment, a forward link 110 comprises a lower segment 112 and an upper segment 114 which comprises a hollow connector portion 116. Lower segment 112 is telescopingly received within hollow connector portion 116 of upper segment 114. Additionally, a longitudinal positioning bar 118 is connected to lower segment 112. Longitudinal positioning bar 118 comprises pluralities of teeth 119 on the right and left sides thereof. A manually operable self-locking release 120 is generally similar to the releases described above but release 120 comprises a second, forward pair of teeth 129 or a sufficiently wide set of teeth for also engaging teeth 119 on longitudinal positioning bar 118. Release 120 is pivotally connected to connector portion 116 of upper segment 114 and is fixed in a longitudinal direction on connector portion 116.

Rear link 130 similarly comprises a lower segment 132 and an upper segment 134 having a connector portion 136. Lower rear segment 132 is telescopingly received within connector portion 136 of upper segment 134. The right and left sides of connector portion 136 have pluralities of teeth for positively and securely engaging teeth 127 on release 120. Release 120 also comprises a biasing member in the form of a spring 128 for normally providing an outwardly biasing force to the handled portion 123 of release 120 thereby urging the teeth 127 of release 120 into engagement with teeth 119 on longitudinal positioning bar 118 and into engagement with the teeth connector portion 136 of rear link upper segment 134. Since release 120 is fixed in the longitudinal directions on the connector portion 116 which is part of upper link segment 114, when teeth 127 of release 120 are positively engaged with teeth 119 of longitudinal positioning bar 118, the longitudinal configuration of the forward link 110 is fixed

In this embodiment, if the telescopic fittings are loose, to ensure the correct angular orientation of the device 140, the operator may need to use one hand to level the device during positioning. Once the teeth of locking member 120 are engaged with positioning bar 118, they are positionally fixed together with upper links 134 and 114. This also fixes the rotational position of device 140. Theoretically if the telescopic and the related pivoting fittings are ideal, the two links will stay in a perfectly parallel orientation even when their lengths are being changed. The telescopic actions of the two links are thus generally synchronized. In other words, in a manner similar to that described above in connection with the embodiment illustrated in FIGS. 3-7, the engagement of the teeth 127 of release 120 with the teeth on connector portion 136 of upper, rearward link 134 maintains the angular or pivotal position of device 140 by preventing relative movement between the forward link 110 and the rearward link 130.

FIG. 17 illustrates this embodiment of the present invention in an elongated configuration wherein the links 110 and 130 have been extended and are locked in position by self-locking releaser 120. FIG. 18 illustrates this embodiment of the present invention wherein release 120 is securing the links in an elongated position as well as securing device 140 in a forwardly pivoted position. From the present description and drawings it will be appreciated that this embodiment of the present invention offers a simple one-hand-operated device positioning support for selectively positioning a device in one of a plurality positions wherein links can be readily elongated or shortened and the support device can be pivoted forwardly or rearwardly, all of which is controlled by operation of a single manually operable self-locking release utilizing the positive engagement of opposing, engageable pluralities of teeth.

FIGS. 19-25 illustrate a further embodiment of the present invention wherein one link is partially disposed within another link. According to this illustrated embodiment, the self-locking release is also partially disposed within the links. FIG. 19 is a side view of this embodiment of the present invention wherein certain internal structures are illustrated in phantom. According to this embodiment, the device 210 is movably connected to base 212 by rear link 214 and forward link 213. Rear link 214 forms a housing having an inner surface comprising inwardly facing teeth 219. A pair of movable locking blocks 215 are movably positioned within housing 214. Locking blocks 215 comprise teeth 225 oriented for selective engagement with the internally facing teeth 219 of link housing 214. Locking blocks 215 are connected to forward link 213 so that when the teeth 225 of locking blocks 215 are positively engaged with the teeth 219 of link housing 214, there will be no relative movement between link 213 and 214. Locking blocks are movable laterally but not longitudinally on forward link 213.

The engagement and disengagement of teeth 225 on locking blocks 215 and teeth 219 on link housing 214 is best shown FIGS. 21 and 23. In this illustrated embodiment, a movable plunger 217 is positioned between a pair of laterally movable pressure pads 216 which can exert outward lateral forces on locking blocks 215. Movable plunger 217 is normally biased upwardly by a biasing member 218 which in this embodiment is in the form of a spring. As illustrated, movable plunger 217 and pressure pads 216 comprise opposing, complementary engageable inclined surfaces. FIG. 21 illustrates movable plunger 217 in its normally biased, upper configuration wherein its outermost inclined surfaces 222 are positioned against the innermost surfaces 232 of the inclined surfaces 234 of pressure pads 216. When plunger 217 is in this position, pressure pads 216 are pushed outwardly thereby forcibly contacting and exerting outward pressure on locking blocks 215. This causes positive engagement between outwardly facing teeth 225 on locking blocks 215 and inwardly facing teeth 219 on link housing 214. Thus when plunger 217 is in a normally, upwardly biased position, the cooperating teeth are engaged and relative movement between the links is prevented.

From the present description, it will be understood that in order to permit relative movement between link 213 and 214, it is necessary to relieve the outwardly directed pressure on locking blocks 215. This is accomplished by moving plunger 217 downwardly against the biasing force of biasing member 218 to a position such as that shown in FIG. 23 where the outermost inclined surfaces 222 of plunger 217 are aligned with the innermost surfaces 234 of the inwardly facing surface of pressure pad 216. This downward movement of plunger 217 is readily accomplished in a one-handed-operation by squeezing a handle 231, which is connected to, and most preferably, but not necessarily integrally formed with, movable plunger 217, toward handle 232 which is connected to, and preferably integrally formed with, link housing 214. FIG. 24 illustrates handles 231 and 232 in a spaced apart configuration due to the biasing force of biasing member 218. Squeezing handles 231 and 232 together causes movable plunger 217 to move downwardly to the configuration shown in FIG. 23, relieves the outwardly directed pressure on pressure pads 216 and permits the disengagement of the engageable teeth and correspondingly permits the repositioning of the device 210 relative to base 212.

FIG. 25 illustrates this embodiment of the present invention after device 210 has been repositioned relative to base 212 and opposing handles 231 and 232 have been released thereby allowing biasing member 218 to return plunger 217 to the upper position shown in FIG. 21 to reengage the opposing sets of teeth and secure the device 210 in the desired position.

FIGS. 26-31 illustrate another embodiment of the present invention which is somewhat similar to the embodiment illustrated in FIGS. 19-25. According to this embodiment of the present invention as best illustrated in FIGS. 28-31, the structure of the release corresponding to the locking block 215 and pressure pads 216 is a single integrally formed locking member 255 which is connected to forward link 243. In this embodiment, rearward link housing 244 also comprises internally facing engageable teeth 249. The plunger 247 is connected to forward link 243 and is normally biased by a pair of biasing members 238 which urge movable plunger 247 upwardly thereby biasing locking member 255 outwardly. Outwardly facing teeth 259 on locking block 255 are normally biased into engagement with the internally facing teeth 249 on the inner surface of the link housing 244.

As in the previously described embodiment, disengagement of the teeth is accomplished by moving plunger 247 downwardly. In this illustrated embodiment, downward movement of plunger 247 is accomplished utilizing lever 276 positioned on an outer surface of housing link 244 and a flexible linkage. Activation of lever 276, which is accomplished by squeezing lever 276 against the handle 286 on the outer surface of housing link 244, draws the outer portion of wire 292 further out of outer sheath 245 thereby pulling the inner end of wire 292 which is connected to plunger 247 downwardly. This pulls plunger 247 into the position in FIG. 30 which permits the disengagement of teeth 259 from teeth 249. In a manner similar to that described above, this permits forward link 243 to be moved relative to rearward link 244 and device 280 to be moved relative to base 250.

According to another embodiment of the present invention at least one release is hidden from view and not directly accessible by the user. For example, if the lower release of the device shown in FIG. 8 is replaced by the release shown in FIGS. 26-31 but without the squeezing lever 276 and the handle 286 whose function are performed by the corresponding structure of the upper release of FIG. 8, then the lower release is hidden and not directly accessible by a user. In a similar manner, the releases of the embodiments shown in FIGS. 19-25 and/or FIG. 26-31 or a combination of them can be used to construct devices comprising a plurality of releases, such as those shown in FIGS. 8 to 11. Some of the releases including the releases for such devices which comprise a plurality of releases can be hidden from view and not directly accessible by hand.

While the manually applied forces described above are squeezing forces, the forces applied to plunger 247 of FIG. 31 and the forces applied by the wire are pulling forces. The manually operable self-locking releases of the present invention are readily adaptable to actuation upon other forms of manual manipulation such as twisting, pushing, pulling or a combination of them. For example, with minor modification lever 276 in FIG. 31 could be mounted so that it is twistable about its pivotal axis 275.

While the preferred illustrated embodiments of the present invention described above use intermeshing teeth to provide a positive engagement for the self-locking releases and prevent undesired relative movement between parallel links, in other embodiments of the present invention, the teeth are replaced with other constraints, e.g. non-smooth frictional surfaces and/or sticky surfaces which prevent sliding under designed loads when biased into contact by a self-locking release comprising a biasing member which biases the surfaces into each other. FIG. 32 illustrates one embodiment of the present invention with non-parallel links 313 and 314 and, instead of teeth, with frictional surfaces 327 on the rear link 314 and fictional surface 328 on the clip surface which contacts the surfaces 327. FIG. 33 is a rear view of the device shown in FIG. 32 with links at an angle, i.e. non-parallel. From this description and the Figures, it will be appreciated that device 310 rotates as its position is changed. FIG. 34 is a side view of the embodiment shown in FIG. 32 with the device 310 in a forwardly pivoted position.

As used herein, the term “constraint” is used to indicate structure, such as teeth, projection(s) or frictional surfaces which, when biased together, prevent relative movement between the links under the designed load to avoid breaking the release. 

1. A device positioning support for selectively positioning a device in one of a plurality of positions, said device comprising: a base, a pair of generally parallel links pivotally connected to said base and to a device, a first one of said links comprising a first plurality of teeth, a manually operable self-locking release comprising a biasing member and a second plurality of teeth, wherein said release is connected to the second one of said links, said release normally biasing said second plurality of teeth into engagement with said first plurality of teeth to prevent relative movement of said first plurality of teeth with respect to said second plurality of teeth, said release manually operable to reduce the biasing force applied to said teeth sufficiently to allow disengagement of said respective teeth thereby allowing movement of said first link relative to said second link.
 2. A device positioning support according to claim 1 wherein said first plurality of teeth are integrally formed on said first link.
 3. A device positioning support according to claim 2 wherein said release comprises a spring-biased clip connected to said second link.
 4. A device positioning support according to claim 3 wherein at least one portion of said clip is pivotally connected to said second link.
 5. A device positioning support according to claim 1 wherein said second plurality of teeth are integrally formed with said release.
 6. A device positioning support according to claim 1 wherein said release is operable by one hand.
 7. A device positioning support according to claim 1 wherein said device positioning support comprises a second plurality of links, a second pair of engageable teeth, and a second release.
 8. A device positioning support according to claim 7 further comprising a linkage connecting said release with said second release, and wherein operation of one of said releases to allow disengagement of said first set of teeth also allows disengagement of said second plurality of engageable teeth.
 9. A device positioning support according to claim 8 wherein said linkage comprising a sheathed wire.
 10. A device positioning support according to claim 1 wherein said device positioning support comprises a device and said device comprises a lamp.
 11. A device positioning support according to claim 1 wherein said links are generally parallel.
 12. A device positioning support according to claim 1 wherein at least one of said links is selectively elongatable.
 13. A device positioning support according to claim 12 further comprising a third plurality of teeth connected to said elongatable link.
 14. A device positioning support according to claim 13 wherein said third plurality of teeth are arranged in a row which is substantially parallel to said elongatable link.
 15. A device positioning support according to claim 13 wherein said release is selectively engageable with said third plurality of teeth to maintain the longitudinal configuration of said elongatable link.
 16. A device positioning support according to claim 1 wherein both of said links are elongatable.
 17. A device positioning support according to claim 16 further comprising a third plurality of teeth arranged in a row which is substantially parallel to said elongatable link.
 18. A device positioning support according to claim 17 wherein said release is selectively engageable with said third plurality of teeth to maintain the longitudinal configuration of said elongatable link.
 19. A device positioning support according to claim 16 wherein at least one of said links comprises a plurality of telescoping elements.
 20. A device positioning support according to claim 1 wherein said second link is at least partially disposed in said first link.
 21. A device positioning support according to claim 20 wherein said release is at least partially disposed in said first link.
 22. A device positioning support according to claim 21 wherein said release is also at least partially disposed in said second link.
 23. A device positioning support according to claim 1 wherein said release is at least partially disposed in said first link.
 24. A device positioning support according to claim 23 wherein said release is also at least partially disposed in said second link.
 25. A device positioning support according to claim 23 wherein said release comprises a sheathed wire.
 26. A device positioning support according to claim 1 wherein said release comprises a sheathed wire.
 27. A device positioning support for selectively positioning a device in one of a plurality of positions, said device comprising: a base, a pair of links pivotally connected to said base and to a device, each of said links comprising a longitudinal axis extending from said base to a device; a manually operable self-locking release comprising at least one projecting member, said release connected to a first one of said links, a second one of said links comprising at least one receptor, said receptor configured to receive at least a portion of said projecting member with said receptor positioned on both sides of said projection generally along said axis; said release normally biasing said at least one projection member into at least one receptor, so that movement of said projection relative to said longitudinal axis of said second link is prevented, and said release manually operable to reduce the biasing force and permit said projection to move out of said receptor.
 28. A device positioning support according to claim 27 wherein said links are generally parallel.
 29. A device positioning support according to claim 27 wherein said projection and said receptor both comprise teeth.
 30. A device positioning support according to claim 27 wherein said receptor comprises a resilient material.
 31. A device positioning support according to claim 27 wherein said release is a one-hand-operated release.
 32. A device positioning support according to claim 27 wherein said device positioning support comprises a second plurality of links, a second pair of engageable teeth, and a second release.
 33. A device positioning support according to claim 32 further comprising a linkage connecting said release with said second release, and wherein operation of one of said releases to allow disengagement of said first set of teeth also allows disengagement of said second plurality of engageable teeth.
 34. A device positioning support for selectively positioning a device in one of a plurality of positions under a designed load, said device comprising: a base, a first pair of links pivotally connected to said base and to an intermediate base, a second pair of links connected to said intermediate base and a device, a first release engageable with said first pair of links to prevent relative movement, under the designed load, between said links of said first pair of links; and a second release engageable with said second pair of links to prevent relative movement, under the designed load, between said links of said second pair of links.
 35. A device positioning support according to claim 34 further comprising a linkage operably connecting said first release with said second release so that the actuation of said first release causes the actuation of said second release.
 36. A device positioning support according to claim 35 wherein said linkage comprising a wire.
 37. A device support positioning support according to claim 35 wherein said linkage comprises a sheathed wire.
 38. A device positioning support according to claim 34 wherein at least one of said pairs of links comprise links which are generally parallel.
 39. A device positioning support according to claim 34 wherein said first pair and said second pair of links comprise links which are generally parallel.
 40. A device positioning support for selectively positioning a device in one of a plurality of positions, said device comprising: a base, a pair of links pivotally connected to said base and to a device, a manually operable self-locking release comprising a first constraint, said release connected to a first one of said links, said release comprising a biasing member which normally biases said first constraint into engagement with a second one of said links.
 41. A device positioning support according to claim 40 wherein at least one of said links is selectively elongatable, further comprising a third constraint connected to said elongatable link, and wherein said release is selectively engageable with said third constraint to maintain the longitudinal configuration of said elongatable link, said release operable to reduce the biasing force applied to said third constraint to allow the elongation of said at least one elongatable link.
 42. A device positioning support according to claim 40 wherein at least one of said constraints comprises teeth.
 43. A device positioning support according to claim 40 wherein a plurality of said constraints comprise teeth.
 44. A device positioning support according to claim 40 wherein said release is a one-hand-operated release.
 45. A device positioning support according to claim 40 wherein said device positioning support comprises a second plurality of links, a second pair of engageable teeth and a second release.
 46. A device positioning support according to claim 45 further comprising a linkage connecting said release with said second release, and wherein operation of one of said releases to allow disengagement of said first set of teeth also allows disengagement of said second plurality of engageable teeth.
 47. A device positioning support for selectively positioning a device in one of a plurality of positions, said device comprising: a base, a first link pivotally connected to said base and a device; a second link disposed at least partially in said first link, said second link pivotally connected to said base and to said device, said second link comprising a second constraint, a manually operable self-locking release at least partially disposed in said first link, said release comprising a first constraint, said release also comprising a biasing member which normally biases said first constraint into engagement with said second constraint.
 48. A device positioning support according to claim 47 wherein said release is manually operable to reduce the biasing force on said first constraint sufficiently to allow disengagement of said constraints thereby allowing movement of said first link relative to said second link.
 49. A device positioning support according to claim 47 wherein said release is a one-hand-operated release.
 50. A device positioning support according to claim 47 wherein at least one of said constraints comprises a plurality of teeth.
 51. A device positioning support according to claim 47 wherein said first constraint comprises a plurality of teeth and said second constraint comprises a plurality of teeth engageable with said teeth of said first constraint.
 52. A device positioning support according to claim 47 wherein said device positioning support comprises a second plurality of links, a second pair of engageable teeth, and a second release.
 53. A device positioning support according to claim 52 further comprising a linkage connecting said release with said second release, and wherein operation of one of said releases to allow disengagement of said first set of teeth also allows disengagement of said second plurality of engageable teeth.
 54. A device positioning support for selectively positioning a device in one of a plurality of positions under a designed load, said device comprising: a base, a first link comprising a first end and a second end, said first link pivotally connected to said base proximate said first end and pivotally connected to a device proximate said second end, a second link comprising a first end and a second end, said second link pivotally connected to said base proximate said first end and pivotally connected to a device proximate said second end, said first link comprising a first plurality of teeth, said second link comprising a second plurality of teeth which are movable relative to said first plurality of teeth when at least one of said links is pivoted relative to said base, said second plurality of teeth arranged for selective engagement with said first plurality of teeth, a manually operable self-locking release connected to said second link and comprising a second plurality of teeth arranged for selective engagement with said first plurality of teeth, said release comprising a biasing member operatively connected to said second plurality of teeth to bias said second plurality of teeth toward engagement with said first plurality of teeth of said first link wherein engagement of said teeth of said second link with said teeth of said first link prevents movement of said first link, under the designed load, relative to said second link, said release manually operable to reduce the biasing force applied to said teeth of said second link sufficiently to allow disengagement of said respective teeth thereby allowing movement of said first link relative to said second link.
 55. A device positioning support according to claim 54 wherein said release is a one-hand-operated release.
 56. A device positioning support according to claim 54 wherein said first plurality of teeth are integrally formed on said first link.
 57. A device positioning support according to claim 54 wherein said release is in the form of a spring-biased clip connected to said second link.
 58. A device positioning support according to claim 57 wherein at least one portion of said clip is pivotally connected to said second link.
 59. A device positioning support according to claim 54 wherein said second plurality of teeth are integrally formed with said release.
 60. A device positioning support according to claim 54 wherein said device positioning support comprises a second pair of links, a second pair of engageable teeth, and a second release.
 61. A device positioning support according to claim 60 further comprising a linkage connecting said release with said second release and wherein operation of said release allows disengagement of said first set of teeth and the second set of teeth.
 62. A device positioning support according to claim 54 wherein said device positioning support comprises a device and said device comprises a lamp.
 63. A device position support according to claim 62 wherein said device comprises a lamp. 